[KerThan]

Hello, I've pretty big problem with pressure-driven flow in simple 2D pipe. I want to push out gas from pipe (N2) via another gas (CH4). For low pressures (max ~500 Pascals on inlet/outlet/internal) everything is okay, but for those that I would like to simulate (atmospheric pressure as internal, flow driven by P ~ 2 atm), everything is running wild. My mesh is pretty good, and I've tried to set up Co to 0.1 but it didn't solve my problem.


Warning that I get:

diagonal:  Solving for rho, Initial residual = 0, Final residual = 0, No Iterations 0
PIMPLE: iteration 1
DILUPBiCGStab:  Solving for H2O, Initial residual = 1.00507e-06, Final residual = 1.73363e-07, No Iterations 1
DILUPBiCGStab:  Solving for CH4, Initial residual = 0.17301, Final residual = 0.00542353, No Iterations 1
DILUPBiCGStab:  Solving for CO2, Initial residual = 1.22766e-06, Final residual = 2.11756e-07, No Iterations 1
DILUPBiCGStab:  Solving for N2, Initial residual = 0.248774, Final residual = 0.00658698, No Iterations 1
DILUPBiCGStab:  Solving for h, Initial residual = 0.760182, Final residual = 0.0245965, No Iterations 1
--> FOAM Warning :
    From function Foam::scalar Foam::janafThermo<EquationOfState>::limit(Foam::scalar) const [with EquationOfState = Foam::perfectGas<Foam::specie>; Foam::scalar = double]
    in file /home/ubuntu/OpenFOAM/OpenFOAM-5.x/src/thermophysicalModels/specie/lnInclude/janafThermoI.H at line 117
     attempt to use janafThermo<EquationOfState> out of temperature range 200 -> 5000;  T = -8.2578

T:

/*--------------------------------*- C++ -*----------------------------------*\
| =========                 |                                                 |
| \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox           |
|  \\    /   O peration     | Version:  5                                     |
|   \\  /    A nd           | Web:      www.OpenFOAM.org                      |
|    \\/     M anipulation  |                                                 |
\*---------------------------------------------------------------------------*/
FoamFile
{
    version     2.0;
    format      ascii;
    class       volScalarField;
    location    "0";
    object      T;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

dimensions      [0 0 0 1 0 0 0];

internalField   uniform 293;

boundaryField
{
    inlet    
    {
        type     zeroGradient;
        value    uniform 293; 

    }
    outlet
    {
        type    zeroGradient;
    }
    frontAndBack
    {
        type            empty;
    }
    
    walls
    {
        type            zeroGradient;
    }
}
// ************************************************************************* //

I've heard that there was option in older versions of OF to fix Lewis number at 1, but I can't find hsEqn file in my OpenFoam version.